#include <stdio.h>
#include <math.h>

int main()
{
    int a,b,c;
    scanf("%d %d %d",&a,&b,&c);
    if(a+b>c&&a+c>b&&b+c>a)
    {
        double x = a+b+c;
        double s = x/2.0;
        double tmp = s*(s-a)*(s-b)*(s-c);
        double area = sqrt(tmp);
        printf("area = %.2f; perimeter = %.2f\n",area,x);
    }
    else
    {
        printf("These sides do not correspond to a valid triangle\n");
    }
    return 0;
}